Display screen or portion thereof with a user interface for a database time-machine



The sole FIGURE is a front view of the claimed design of a display screen or portion thereof with a user interface for a database time-machine.

The outermost broken lines in the FIGURE illustrate a display screen or portion thereof and form no part of the claimed design. The other broken lines in the FIGURE illustrate portion of the graphical user interface that form no part of the claimed design. The gray filled areas in certain FIGURE represent a contrast in appearance between the gray filled areas and the non-gray filled areas of the claimed designs. The same density or darkness gray filled areas represent a similar appearance in those areas. 

CLAIM We claim the ornamental design for a display screen or portion thereof with a user interface for a database time-machine, as shown and described. 